1. Field of the Invention
This invention relates to a semiconductor device, in particular, to a semiconductor device including a metal/high-k gate structure.
2. Description of Related Art
In metal gate/high-k (MG/HK) technology, work-function control is a key to adjusting Vth (threshold voltage) of the transistors. FUSI, or fully silicided, metal gate is one of the MG/HK solutions to control the work-function.